Wheel brake control linkage for roadable airplanes



June 27, 1950 R. E. FULTON, JR, ET AL 2,512,928

WHEEL BRAKE CONTROL LINKAGE FOR ROADABLE AIRPLANES Filed March 5, 1945 5 Sheets-Sheet 1 June 27, 1950 R. E. FULTON, JR., ET AL 2,512,928

WHEEL BRAKE CONTROL LINKAGE FOR ROADABLE AIRPLANES Filed March 3, 1945 5 Sheets-Sheet 2 Elma/WW may? 1mm, (fr: "w fic'iazfia JJ/mrez June 27, 1950 R. E. FULTON, JR., ET AL 2,512,928

WHEEL BRAKE CONTROL LINKAGE FOR ROADABLE AIRPLANES Filed March 5, 1945 5 Sheets-Sheet 5 a4 45 44 as 4 4a 42 2a 55 {/0053 J00 June 27, 1950 R. E. FULTON, JR., ETAL 2,512,928

WHEEL BRAKE CONTROL LINKAGE FOR ROADABLE AIRPLANES 5 Sheets-Sheet 4 Filed March 3, 1945 3mm e flfleri E 1 2011011, f17 "5 0010 June 27, 1950 WHEEL BRAKE Filed March 3, 1945 R. E. FULTON, JR., ET AL 2,51

CONTROL LINKAGE FOR ROADABLE AIRPLANES 5 Sheets-Sheet 5 Patented June 27, .1950

UNITED Y STAT Es P TE T I WHEEL BRAKE CONTROL LINKAGE ron nos-mew Americans Robert E.- Fulton, IJL, Washington, .'D.. .C., and Octavio Jose Alvarez, New'iYgrk, N. 2., assignms to Continental, Incorporated, Washington, D..-,C., acorporation of Connecticut 1945, Serial N0. 580,846

Application March 3,

Claims. (01. 244 2) This invention relates to a vehicle primarily not infrequently at considerable distance. Thus the time saved by the speed of aerial transportation is more frequently than not consumed 'by the ground-travel time required to get from the airport to the fliers final destination.

Furthermore, the expense of travel between the airport and the community, usually involving taxis, is not inconsiderable. When to this is added the initial cost-and upkeep of the airplane plus that of an automobile which the flier undoubtedly owns as well, it is obvious why few can afford to own an aircraft. -The average automobile ride from point of origin to destination is not over five miles. For every automobile trip of several hundred miles, the average man makes as many as a hundred short local trips. Since he can afford only an automobile or an-airplane, his choice is obvious. This has been the basic factor in retarding widespread public adoption of the airplane in the -While the real cure-has been much discussed,

an automobile-an expensive and unnecessary procedure which has done more than any other thing to stifle'aviation; Others have recognized this fundamental cessity located on the outskirts of communities, .1 i

.2 problem and have made efforts to solve it by accomplishing a transition from airplane to .car and back; But the problem has many .as-.- pects mechanical, aerodynamic, .practical, safety, economy, comfort, service and maintenance, public reaction and acceptance- Of the several suggested solutions which have :been ;of-

iered .to date, all have failed due to neglectlof oneior more of the above features tMost have been so radical iniconception and based on such untried principles that they have failed to hold public interest. Others have made contributions which, unless supplemented by many additional features, wereof little practical value.

readable airplane by making a practical combination of already accepted forms andstyles of automobile and aircraft designs, thereby maks ing the final-unit one .of greater public value by virtue of its ready-acceptance resulting mm its being basically a-com bination of already familiar elements; i

The present invention therefore is concerned with an airplane having a removable section adapted for use as a standard automobile and an airplane section comprised of wings, fuselage and control surfaces, having cooperating in te-rlocking -means cnthe airplane and automo. bile sections by which the-sections :maybe firmly held together to establish a complete airplane.

This interlocking means is not disclosed here.

as it constitutes "no part of the present invention, but a-suitable means is disclosed in application Serial No. 5'80,-844 filed herewith. I

When the completed airplane is-being used- 1 01" air travel, it should be controllable in the usual manner for airplanes. This includes the provision of foot pedals which may be freely pressed upon by the operator to *move the rudder at the tail end of the fuselage. When thenautomobile section' is used alone for road :travel however, at least one of the pedalsshould' be useable to control the movement of the automobile/in the usual mannerj As it is probable that it is of greatest importance trom a safety viewpoint that the brakes .be operated iby the conventionally placed foot pedal, the present invention Lutilizes this corresponding foot .pedal .to apply :the brakes; it is also import-ant, however, that this pedal-'be' freed of :operation of the brakeslwhe'n the vpedalsare utilized to move the rudder.

"The inventiontherefore,:involvesth 'ipn visi n of foot pedals one of which operates -J;he--,brale s ofthe automobile.se tiomdurinsrqad traveLand both of which are -;utiliz,ed to :move {the rudder It is an object of this invention to produce a 3 of the completed airplane during air travel. When controlling the rudder the pedals are interconnected so that the one moves forwardly as the other moves rearwardly.

As a further safety feature of the invention, the rudder connected to the foot pedals is main tained at all times and it is, therefore, certain that during air travel this connection will be intact. When the airplane section is removed from.

the automobile section for road travel, the connection to the rudder may bebroken or disconnected adjacent to the point of separation between the sections, but in accordance with the invention this will be the onlyinterruption in the connection, as the engagement at the pedals will be maintained constantly.

The invention also involves the provision of 7 means for eliminating the braking action during air travel so that the pressure required to operate the brakes will not have to be exerted during use of the pedals for rudder movement. The two 'pedals will therefore act under substantially the same foot pressure throughout both ranges of movement in moving the rudder, as the one whichis also used to operate the brakes will be fully relieved of this braking action.

As a further feature of the invention, means are provided for quickly and effectively eliminating the braking action from the brakefoot pedal, and this means is conveniently manipulatable by the operator.

Another feature of the invention is the. provision of means for including or excluding the braking action from the pedal control, which will be positive in its operation. When the brake pedal is coupled to applyv the brakes, this coupling will be immutably maintained. Also when the brake pedals are operating only the rudder, the braking system will be maintained incapacitated.

Other features of the invention will be evident f from the following description and from the drawings, which disclose a preferred structural embodiment of the invention.-

. In the drawings:

Figure 1 is a side elevation of the airplane as associated systems;

Figure 4 is a section on the line 44 of Figure 3;

Figure 5 is a sideelevation of the foot pedals and their immediate coupling elements;

Figure 6 is a plan view of Figure 5;

Figure 7 is a section onthe line 1-1 of Figure 6;

Figure 8 is a perspecti e of the shifting element in the structure of Figure 7;

Figure 9 is a plan view of the brake linkage coupling device in its coupling position, the cover plate being removed;

Figure 10 is a plan view similarto Figure 9, of

the'device in its brake uncoupling position; and

Figure 11 is a vertical longitudinal view" through the brake linkage device in the position of Figure 9. a I w Referring first to Figure l, the autom'obilesection I of the airplaneappears'at the left ofv the vehicle and the airplane section 2 appears at the right of the vehicle. In Figure 1 these two sections are combined for flight and in Figure 2 they are separated from each other so that the automobile section may be driven independently as a unit for road travel. When the automobile section is used as a unit the airplane-section 2 is left behind.

; The airplane section 2 includes lifting wings 3 at its forward portion and at the trailing edges of these wines are the usual ailerons 4. At the rear of the airplane section are the usual control surfaces and these include the rudder 5 and the elevators 6.

When the airplane section is attached to the automobile section as shown in Figure l, the airplane section ,is supported as a cantilever as shown in Figure 1. The means for attaching these sectionstogether and by which the sections may be released from each "other constitute no part of the present invention and consequently are not shown in detail, but a suitable means is disclosed in application Serial No. 580,844 filed herewith. When this interconnecting means is released and the sections are separated from each other, the airplane section must be self-supporting and to accomplish this it is provided with the wheel I beneath the tail surfaces and theuwheels 8 beneath the forward wings.

Just prior to the time that the airplane section is separated from the automobile section, the wheels I and 8 are'moved downwardly into contact with the ground. The means by which the wheels I and 8 are moved downwardly are not a part of the present invention andthereport the airplane section in the same position which it would occupy if'it were attached to the automobile section so that separation of the sections and their reconnection is facilitated. The automobile section I includes the front wheels in and the rear wheels II. It also includes a motor to which the propeller l3 may be attached for air travel, as shown in Figure l, or from which it may be removed for roadptravel, as shown in Figure 2. A steering wheel I4 within the cab portion of the automobile section is provided so that thefront wheels I0 may be turned to guide the automobile during groundtravel or so that certain control surfaces of theairplane section may be moved during air travel. The means by which the operation of the steering wheel produces control for road travel and for air travel is not a part of the present invention. A suitable mechanism of this character is disclosed in application Serial No..580,847, filed here with, now U. S. Patent No. 2,457,884, issued on Jan. 4,1949. p. I

.Within the cab and accessible to the operator are foot pedals I5 and 16. During air travel these pedals are operated to move the rudder at the rear end of the airplane section and during road travel, in accordance-with the present invention, one of'these pedals is utilized to operate the brakes within the wheels in and H. l Itmay first be explained that during road travel one of these-pedals is not required to controla clutch-inthe automobile. In accordance with the present invention, the driving connection between the motor and the wheels is entirely under the control of the accelerator pedal so that when no pressure is exerted upon thislpedal the motor is in. efiectdisconnected from thedriving wheels. Pressure upon the accelerator pedalnot only establishes a driving connection between the motor and the driving wheels but determines'the speed at which the automobile will the driven. However, this control means'which is responsive to the accelerator pedal does not .constitute a part of the present invention.

The pedal I5 is a lever which is pivoted ata pointbetween its ends about a fulcrum bolt I5! (fig. 5). The fulorum'bolt iscarried at-the outer extremities of bracket plates,,|8- and t9 (Figs 5 and 6) which are secured to transverse bars;2|l and 2| of the automobile section framework and'the pedal lever |5 fits closely between the brackets I8 and I9. To limit the forwald movement of the pedal, it is providedwithanzadjustable stop screw 23 (Fig. 5) whichmay strike against a stopplate 24 secured to the cross bar 2|.

Thepedal I6 is pivoted in the same manner that pedal I5 is pivoted and this includes bracket plates :25 and 26 (Fig. 6) which are attached to the cross bars 20 and 2|. Stop screw 2'land stop plate 28 are provided to limit the ,forward' movement of this pedal.

Thelower end of lever I5 is pivoted by bolt :30 to a, link' 3| (Fig. 6), the other end of .this link 3| being pivoted bya pin 32 to a lever. 33 (Fig. 6). In like manner, the lower end of the lever |;6 is connected by a link 34 to the lever.-;3 3 at apin 3.5. Thelinks3| and 34are adjustable so that their lengths may be varied and when the pedals ;|;5 and it are in their mid-positions, the :lever 33 should preferably extend in a direction whichis substantially parallel to a line joinin the pedals as appears from Figure 5.-

The lever 33 (Fig. 6 is pivoted at a point midway between pins 32 and 3.5 byafulcrumbolt 36. This lever 33 extends through atransverse slot-'31 through a hollow squarebar 3B;whic h extends longitudinally of the automobile framework. The fulcrum bolt736 is supported both aboveand below the lever '33 by the upper and lowerremaining walls of the;hollow square frame member 38.

The lever 33 and its connection bylinksf3| and 34 to the pedals I5 and I6, respectively, cause the pedals I5 and |B-to move in unison with each other but in opposite directions. -Thus, pressure upon the one pedal in one direction will for e the other pedal to have an equal movement butjn the opposite direction.

Outwardly beyond the pivot pin 32 from the fulcrum bolt=35 is a pin 4|. One end .ofa cable 42'is. attached to pin 4| by a clevisq43 and .aclevis 44 also connected tothe pin 4| attaches a. cable 45 to the lever 33. The cable 45 passes around a sheave 46 supported by'the automobile framework. The cables 42 and 45 extend rearwardly and may be connected directly to the rudder :5

or may be connected to a coupling which will;per-.

mit a quick separation between the automobile and airplane sections.

Movement of the pedal levers I5 and. I-LE therefore pulls on the cables 42 and 45 to turn-the rudder 5 and since the pin 4| has a longer moment arm than do the pivot pins :32 .ands35, the movement of the pin4| is increased. This'is desirable in some instances in order to giveth'e cables-4=2 -and 45 an increased movement with respect to the pedal travel.

A'link 50 (Fig. 6) is connected bya pin 49 to the lever :33 at V a point between the. pivot. pin :35 and the-fulcrum bolt 36. -Thislink 50 extends into a disengageable connecting =Idevice which cons-ti:-

tutes;anrimportantfeature of theinvcntion. This disengageable connecting device may either es: tablish a driving connectionbetween the link extending into one end thereof and the link 5]. extending .out of the opposite I end thereof, or may break thisconnection so that movementof link 50=wil1 not vbe transmitted to link 5|.

-The.disengageab1e connection device includes an upper plate-.52 and a lower plate 5.3 (Fig. 10,). These plates are separated from each other a fixed distance by spacer collars 5.4 (Fig.9) through which clamping bolts pass. Two of these bolts, 55, are'on opposite sides of the 1ink5|l and rollers 56 (Figs.9 and 1.0) are rotatably mountedupon the collars .54 on these bolts. Bearing plates :51 (Fig. 9) are secured to the opposite sides of link 50 to provide flat surfaces which are in contact with the rollers 56 to provide a guide for the lengthwise movement of the link .58. A pressure plate .58 (Fig. 10) is securedto the end of the link 50 and at its point of attachment to the link 5.0 it is perpendicular to the link but to one side thereof it is curved as indicated at 59 (Fig. .9).

The link 5| is similarly guided'by means of bearing plates 60 (Fig. 9) affixed thereto which bear upon rollers 6| (Figs. :9 and 1.0) rotatably mounted on the collars-54 of two other securing bolts.62. A pressure plate .63 is secured to the endof the link 5| andhas a configuration similar to that of plate-5.8. It will be noted that the plates 58 and :63 are spaced'from each otherand are symmetrical about a point centrally between them.

Between the plates 58 and-.33 is a generally oblong shapedplate- 64. Its longer dimension is such as to bridge the space between the plates 58 and :63 so that pressure from the plate :53 will be transmitted directly to the plate 6.3, as appears :from Figure 9.' However, when this plate 64 is'turned crosswise to the position of Figure 10this connection between the plates 53 and $3 will *be broken because the narrow width of the plate 64 is then presented between the platesn58 and 63. When the plate 64 is in this position of Figure 1.0, the plate 58 and the plate 63 may have independent back and forth movement, and movement of the one will not be transmitted-to the other. v

To turn the plate 64 from the position of Figure 9 to the position of Figure 10, a turning mem ber shown in Figure 8 is provided. This includes a central fulcrum stem-66 which passes through pivot bearing openings in both the upper plate 52 and the lower plate 53. Secured to the upper end-of the fulcrum stem 66 and on the outside of the'plate 52 is a plateB'l from which project pins 68 and 69. The pins 68 and 53 are parallel to and equidistant from the fulcrum stem-66-and are at'diametrically opposite points from each other with respect to the fulcrum stem 63.

The pins 68 andGS pass through openings "1| and '12 (Fig. 9), respectively, through both the upper plate 52 and the lower plate53 and these openings H and 12 are of-arcuate shape to permit-the arcuate -movement of the pins .68 andalit when stem is rotated. The arcuate openings H and '12 are only long enough to permit a .quare ter turn of the fulcrum stem 56 and thus serve to limit itsrotational movement to the position inFigure 9 in one direction and to theposition in'Figure lO in the. opposite direction.

-A retainingplate 13 (Fig. 7) is carriedupon the stem-.66 and pins 68 and .69 on theirv portions.

which project beyondthe lower'platel53. 'eThe.

pins':-.GB-.and 39 (Fig. 8) arethreaded. andithese.

respectively. These rollers 80 and 8| are spaced from the inner faces of the plates 52 and 53 by means of washers 82 and 83. The plate 84 is formed with a longitudinally extending centrally located slot 84 (Fig. 9) which is only as wide as the outer diameter of the rollers 80 and 8| so that the plate 64 is limited only to lengthwise movement along the rollers 80 and 8|. The rollers 80 and 8| when in the position of Figure 9 therefore serve to guide the plate 04 in a lengthwise direction and maintain its position as a con?- necting bridge between the plates 58 and 83. .The plate 64 is also maintained in its position of Figure 9, due to the curvature of portion 59 of plate 58 and the corresponding curved portion of plate 63. This curved portion close to the flat portions of the plates 58 and 83, lies'slightly within an arc struck from the center of stem 88 so that there will be a camming action tending tomaintain the plate 64 in the position of Figure 9.

Due to the close fit of the rollers 80 and BI with respect to the width of the slot 84, the plate 64 will be carried by them to the position of Fig.- ure 10 upon rotation of the fulcrum stem 66. To turn the fulcrum stem 86 andthereby turn the plate 64 to the position of Figure 9 or Figure 10, an adjustable arm 85 (Fig. 7) is affixed to the plate 61. A Bowden wire 86 (Fig. 6) is connected to the outer end of the arm 85 and this Bowden 'wire extends upwardly to a point within the automobile cab to be accessible to the operator. As here shown, the end of the wire 86 is connected to a manually operable lever 81 (Figs. 1 and 2) within reach of the operator. This leverisrmore fully disclosed in application Serial No. 580,845 filed herewith now U. S. Patent No. 2,509,095, is sued on May 23, 1950. Movement of this lever back and forth causes the arm 85 to move and thereby turn the plate 84 to the position either to establish or break the connection between the links 50 and 5|. I

When the plate 64 is in the position of Figure it is preferable that the plate 84 be maintained in a substantially symmetrical position with respect to the rollers 80 and 8|. This is desirable because if the plate 84 moves endwise so that the roller 80 or BI is at its respective end of the slot 84, it will be difficult to turn the plate 64 from the crosswise position to the position of Figure 9 since one end of the plate 64 will first come into contact with its respective plate 58 or 63. Under these conditions, in addition to the force required to turn the plate 84 to the position of Figure 9, force will have to be exerted to shift the plate 84 lengthwise under the camming action of its end as it moves along the plate 58 or 83 with which it is in contact.

However, if the plate 64 is in the symmetrical position of Figure 10 rotation of the plate 64 toward the position of Figure 9 will cause its two ends uniformly to approach the plates 58 and 63, and the plate 84 will move freely into the position of Figure 9. Any slight displacement of the plate 64 from a symmetrical position as the position of Figure 9 is approached, will be ac-. commodated by the curvature of the portion.59 of plate 58 and the corresponding curved portion of plate 83. Also, the sloping faces89 of plate 84v serve to guide the plate into position between the pressure plates 58 and 63. I To cause this symmetrical position of plate 64 when in the position of Figure 10, a bolt (Fig. 10) is provided, which passes through the plate 64 andsecures rollers 9| to its opposite sides. Openings are formed in the plates 52 and 53 to receive these rollers 9| and at one end of these openings they are reduced in size to a notch 92. (Fig. 9) which is of substantially the same size as the rollers 9|. These notches 92 are so positionedthat when the plate 84 is in the position of Figure 10 and rollers 9| are in the notches, the plate 64 will be held in the desired symmetrical position. 1

From" this notch 92 the sides 93 and 94 of the openings are curved to serve as guides to direct the rollers 9| into the notch 92 from whatever. lengthwise position the plate 88 may have when it is disposed lengthwise between the plates 58 and 63 as in Figure 9. The curved surfaces 93 and 94 are joined by an edge 95 which is substantially parallel to the lengthwise movement of the plate 64 when, in the position of Figure 9 and is sufliciently long to permit movement of the rollers 9| to the extremities of the positions to which they are carried by the plate 64.

To support the disengageable connecting de-' vices at its rear end, it is attached by a bracket 96 (Fig; 5) secured beneath the bolts 82, to a cross .bar 91 of the automobile framework. A

bracket 98 (Fig. 6) also attached to the cross bar 91 is secured to the disengageable connect-- ing device by bolts 99. Opposite from the bracket:

98 the device fits in between the upper and lower walls of the hollow square bar 38 of the machine:

crum bolt I04 from the pivot pin I03, a pivot pin- |08 (Fig. 3) connects a push rod I09 to the'lever |02. This push rod I09 extends'into a pressure cylinder IIO which delivers fluid to apply the I brakes. A tension spring III (Fig. 5) serves to Withdraw the push rod I09 from the cylinder I I0.

Beyond the pin I08 a cable II2 isattached to the lever I02 at a pivot pin II3 (Fig. 3) and this cable |I2 extends upwardly to a hand brake lever 4 (Fig. 3). The brake lever H4 is of a conventional type which may be locked in position by a hand releasable ratchet. When the hand brake is applied it draws on the cable H2v and forces the pushrod I09 toward the pressure cylinder 0 to apply the brakes in the same manner that this is performed by pressure of the link 5| against the opposite end of' the.

lever I02. .1

Operation of the hand lever II4 to apply the brakes is not interfered with by the connections to the foot pedal since the plate 63 is merely.

drawn away from the plate 84 andno resistance. is offered to such movement and this is true irrespective of whether the plate is in the position of Figure 9 or 10. When the foot pedal is pressed upon to apply the brakes, movement of the lever I02 merely causes a slackening of the cable H2.

and consequently the connection to the hand lever 4 offers no, resistance to such movement.

.It is important to note that the brakes mayalwaysbeapplied by the hand lever ||.4. When the plate 64 has been moved to the position of Figure 9, the brakes may also ibe applied by foot pressure upon the pedal !6, this connection being established by the plate 64. When the plate 64 is moved to the position of Figure 10, it breaks the connection to the brake mechanism so that the link 56 has a lost-motion and no resistance is offered by the brake mechanism to its free movement.

It is also important to note regardless of the position of the plate 64, the foot pedals are always permanently connected to the rudder cables. This is an important safety feature in that it completely eliminates any danger of the airplane being taken off the ground with the rudder controls out of operation.

What is claimed is:

1. In a roadable airplane including an automobile section which may be removed from an airplane section, said automobile section comprising a power unit, wheels for road travel and a brake mechanism, and said airplane section comprising lifting wings and control surfaces including a rudder, the combination in said automobile section of a pair of foot pedals pivoted to receive foot pressure, an interconnection between said pedals so that the one will be moved by the other in the opposite direction, an attachment to said pedals for connection to the rudder to cause its movement, and a connection from one of said pedals to exert a pushing force upon the brake mechanism to apply the brakes, said last named connection including a bridging member longer than wide and disposable in a lengthwise position to transmit the pushing force to the brake mechanism or disposable in a crosswise position to break the application of said pushing force to the brake mechanism.

2. In a roadable airplane including an automobile section which may be removed from an airplane section, said automobile section comprising a power unit, wheels for road travel and a brake mechanism, and said airplane section comprising lifting wings and control surfaces including a rudden, the combination in said automobile section of a pair of foot pedals pivoted to receive foot pressure, an attachment to said pedals for connection to the rudder to cause its movement, and a connection to one of said pedals to exert a pushing force upon the brake mechanism to apply the brakes, said last named connection including a bridging member longer than wide and having a longitudinal slot therethrough, and a shifting member located in said slot to dispose the bridging member in a lengthwise position to transmit the pushing force to the brake mechanism or to dispose it in a crosswise position to break the application of said pushing force to the brake mechanism, said shifting member serving as a guide within the slot to maintain the bridging member in its lengthwise position.

3. In an automobile section which may be connected to an airplane section having lifting and control surfaces to form an airplane, the combination of a pair of foot pedals, a connection to the pedals for operating engagement with a control surface of the airplane section, a disengageable device having oppositely disposed movable pressure plates therein one of which is connected to one of said pedals, an oblong pressure transmitting member between said pressure plates, means for shifting the pressure transmitting member to a lengthwise position to bridge free for independent movement, said pressure;

the space between said pressure plates or to a crosswise position to leave the pressure plates plates being curved to one side of the line of application of pressure to exert a camming action tending to maintain the pressure transmitting member in its longitudinal position, and the other of said pressure plates being connected to the brake mechanism.

4. In an automobile section which may be a connected to an airplane section having lifting and control surfaces to form an airplane, the combination of a pair of foot pedals, a connection to the pedals for operating engagement with a control surface of the airplane section, a disengageable device having oppositely disposed movable pressure plates therein one of which is connected to one of said pedals, an oblong pressure transmitting member between said pressure plates, means for shifting the pressure transmitting member to a lengthwise position to bridge the space between said pressure plates or to a crosswise position to leave the pressure plates free for independent movement, said pressure plates being curved to one side of the line of application of pressure to exert a camming action tending to maintain the pressure transmitting member in its longitudinal position, means to guide said pressure transmitting member to a symmetrical position when in its crosswise position, and the other of said pressure plates being connected to the brake mechanism.

5. In an automobile section which may be connected to an airplane section having lifting and control surfaces to form an airplane, the combination of a pair of foot pedals, a connection to the pedals for operating engagement with a control surface of the airplane section, a disengageable device having oppositely. disposed movable pressure plates therein one of which is connected to one of said pedals, an oblong pressure transmitting member between said pressure plates, means for shifting the pressure transmitting member to a lengthwise position to bridge the space between said pressure plates or to a crosswise position to leave the pressure plates free for independent movement, said pressure plates bein curved to one side of the line of application of pressure to exert a camming action tending to maintain the pressure transmitting member in its longitudinal position, a pivoted lever to which the other of said pressure plates is connected, a brake applying element connected to said lever on the opposite side of said lever from its fulcrum, a hand brake member, and a cable connecting said hand brake member to the same side of said lever to which the brake applying element is connected.

ROBERT E. FULTON, J R. OCTAVIO JOSE ALVAREZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,662,306 Fokker Mar. 13, 1928 2,215,003 Johnson Sept. 17, 1940 2,241,577 Beals, Jr. May 13, 194-1 FOREIGN PATENTS Number Country Date 559,817 Great Britain Mar. 7, 1944 

